Breast pumps are well known, and generally comprise a hood or shield that fits over the breast, a vacuum pump connected to the hood for generating an intermittent vacuum (or negative pressure) within the hood, and a receptacle for expressed milk. The intermittent suction action of the vacuum pump serves to pull on the breast and nipple and thereby extract milk. The extracted milk typically flows from the hood into a collection container for storage and later use. A breast pump of the foregoing type is shown in Larsson U.S. Pat. No. 4,857,051, the disclosure of which is incorporated herein by reference for further details of a breast pump assembly in general.
Inserts for use within the hood of a breast pump are known, but they have typically been used for sizing the breast shield. A flexible breast engaging device has also been used for nipple stimulation, as disclosed in Larsson U.S. Pat. No. 5,049,126. The '126 patent discloses a frame made from a rigid material having a funnel shape. A flexible membrane fits over the nipple receptor frame. When suction is applied to the flexible membrane, it collapses and gently squeezes the nipple for inducing uterine activity.
While various prior art breast pump constructions have been quite effective, there are certain drawbacks associated with some of these constructions. For example, there has been a problem with bacteriological contamination is some previous breast pumps when a motor driven pump is used. Overflow protection is necessary to prevent milk from entering the pump air line. Even so, it has been found that moisture and the like from the user may still enter the pump air line.
Another design consideration for breast pumps is associated with the maintenance of the breast pump in a sanitary condition. In particular, depending upon the configuration of the interior walls of the hood body, it can be difficult for some users to properly clean the device. More specifically, the internal wall construction of the hood body of some previous constructions can have crevices and small passageways that are not easily cleaned.
Accordingly, it is desirable in a breast pump assembly to reduce contamination of the motor air line associated with certain motor driven pumps, and to provide a breast pump that is easily cleaned by a user.